hi uoffl. i grew up in a town with a lot of asians so while i'm not asian i think i get where you're coming from a little as i've had a number of asian girl friends over the years. the pressures to succeed put on the asian kids by the parents in my town were incredible and dating was commonly discouraged until one was a bit older. so, i don't agree with that mentality (and my parents had that mentality too!), especially if your bf was able to maintain high grades while you guys lived together, i do understand and feel for you.
your parents are probably pretty strict but his do sound quite controlling. he will need to stand up to them eventually or he's going to be letting them control him, and you, for the rest of his life. what about telling him that he needs to tell his parents about you before you move with him to grad/med school? i think you will have to set your boundaries with him and make it very clear what you will and won't accept otherwise his parents will be ultimately running your relationship even if you're not living near them. what i'm not suggesting is you start being pushy or tell him what to do all the time but rather make it clear what you can accept. the thing is though only you can decide what is acceptable for you.
if you were to say, for example, that you wouldn't move with him to med school unless he tells his parents beforehand and you even got to meet them before moving, then if he didn't agree to it you'd have to not move with him. maybe that would be too drastic for you, but i think you can start asking now for more of what you want in this relationship. it does sound like he cares about you but is just really under his parents' thumb. maybe start with something small and tell him you'd like to be included more when he does things with his friends and see how that goes. you could tell him what you've said here about wanting your lives to be more intertwined with family and friends. i hope you keep posting. i think you'll get some good help here. i know it's not easy to stand up for one's self and ask for what you want but it is ok. i think you'll know if you've gone too far and it doesn't sound like you will.